Browsing by Subject "Titanium"
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Item A Comparison of the Ligation Torque Expression of a Ribbonwise Bracket–Archwire Combination and a Conventional Combination: A Primary Study(Hindawi, 2022-09-28) Lin, Bin; Jiang, Feifei; Chen, Jie; Liang, Jiaxing; Mechanical and Energy Engineering, Purdue School of Engineering and TechnologyObjective: To assess the effect of the third-order mechanics of a new ribbonwise bracket-archwire combination using an orthodontic torque simulator. Material and Methods. An orthodontic torque simulator was used to measure the third-order moment of a maxillary central incisor as it changed from a neutral position to a 40° rotation in 1° increment. A new ribbonwise bracket (Xinya, China) was compared with a conventional ligation bracket (American Orthodontic, U.S.A.). The effects of different archwire sizes (i.e., 0.017″ × 0.025″ and 0.019″ × 0.025″) and materials (i.e., nickel-titanium, titanium-molybdenum alloy, and stainless steel) were analyzed. Paired sample t-tests were conducted to compare the moments between the two bracket types corresponding to each of the archwires. The effects of the stiffness of the bracket-archwire complexes were also assessed. Results: Statistically significant differences (P=0.05) between the moments from the two brackets were found. The ribbonwise bracket-archwire complex generated larger moments when the rotation angle was lower than 30°. The ribbonwise brackets produced moments that could reach a threshold of 5 Nmm more quickly as the angle was increased. The higher the stiffness of the complex, the larger the moment. Conclusion: The ribbonwise bracket-archwire complex reached the moment threshold limits earlier than the conventional complex. When the rotation angle is less than 30°, the ribbonwise bracket-archwire complex generated a greater torque moment in comparison with the conventional complex.Item A Frictional Evaluation of a New Surface-Modified Titanium Orthodontic Bracket(2000) Olsen, Marc E.; Oshida, Yoshiki; Andres, Carl J.; Katona, Thomas R.; Moore, B. Keith; Roberts, W. Eugene; Shanks, James C.Sliding mechanics is a popular method of moving teeth orthodontically. Sliding mechanics refers to the guiding of a tooth by means of the bracket slot along an archwire in response to some applied force. This concept of tooth movement is subject to both static and kinetic friction. An accurate evaluation of an appliance's frictional properties enables a clinician to identify applications where the utilization of a new appliance may be advantageous. The aim of this study was to evaluate the frictional properties of this new surface-modified titanium orthodontic bracket compared with a traditional stainless steel orthodontic bracket and a currently available non-surface modified titanium bracket. Fifteen brackets (5 Stainless steel, 5 Titanium, 5 Coated Titanium) were combined with five archwires from each material type (SS, NiTi, βTi). Frictional evaluation was completed on each bracket material utilizing .021" x .028" size archwire materials in a specially designed apparatus under wet conditions. The frictional resistance was measured on an Instron Universal Testing machine (Instron Corp, Canton, Mass). The brackets/archwire samples were tested one at a time individually. In addition, a single bracket/ archwire sample from each group was repeatedly tested five times. Measurements were made at every 0.1mm for 30mm via a computer attached to the testing machine. An ANOV A was used to determine differences between groups. The results indicate that stainless steel brackets exhibited significantly better static and kinetic frictional properties than the titanium brackets. Stainless steel wires possessed superior frictional properties to NiTi and β-Ti wires. NiTi wires were generally superior than β-Ti wires. As brackets and archwires were reused, the overall frictional values showed a distinct trend to increase.Item An Analysis of the Fatigue Resistance of Beta Titanium and the Effect of Spot-Welding Upon the Fatigue Resistance of this Alloy(1984) Wong, Michael B.; Garner, LaForrest; Baldwin, James; Moore, Keith; Barton, Paul; Shanks, JamesThis investigation was designed to establish a fatigue curve for beta titanium, determine the effect of spot-welding upon the fatigue resistance of this alloy, and provide qualitative observations about surface characteristics of different batches of TMA in relation to their fatigue lives. Rectangular .016" x .022" 1MA was evaluated. Twelve specimens in each group were tested, making the total sample size 108. The wire samples were evaluated using a cantilever bend test in which specimens were stressed cyclically at varying deflections. Two welded groups were also tested. An auxiliary .016" x .022" TMA was welded to a main test segment of TMA with the .016" side against the opposing .016" side. The weld overlap varied at 25% for one group and 50% for the other. These specimens were stressed at the area adjacent to the weld. One specimen from each group was viewed under the scanning electron microscope to evaluate the fractured area. Specimens from three different batches of 1MA were tested and their fatigue lives compared at .625 inch deflection. One specimen from each batch was viewed under the scanning electron microscope to evaluate its surface structure. A fatigue curve for TMA was plotted from the data. At .625 inch deflection, welding an auxiliary onto the main segment significantly decreased the fatigue resistance of the wire. However, both welded groups had comparable fatigue lives. These wire specimens fractured at some point adjacent to the welded site. Fatigue resistance differed significantly between one batch of TMA and the other two. The scanning electron micrographs of representative specimens from each batch seemed to indicate that the fatigue resistance of each batch was inversely related to its surface roughness.Item Bone regeneration in novel porous titanium implants(2010) Khouja, Naseeba, 1981-; Chu, Tien-Min Gabriel; Brown, David T.; Platt, Jeffery A., 1958-; Blanchard, Steven B.; Levon, John A.The objective of this study was to evaluate the in vivo performance of the novel press-fit dental implant fabricated via electron beam melting (EBM, Southern Methodist Univ.) and compare it to a commercially-available porous-coated press-fit dental implant (Endopore, Innova Corp.). Twelve cylindrical shaped implants 3 mm in diameter x 5 mm long were made by EBM (Southern Methodist Univ.) using Ti6Al4V ELI alloy. Twelve commercial implants (Endopore, Innova Corp.) of the same geometry were used as controls. Samples were implanted in rabbit tibia and retrieved six weeks postoperatively. Six specimens from each implant type were embedded undecalcified, sectioned, and stained with toluidine blue (Sigma) for histomorphometry analysis. Bone-to-implant contact (BIC) was measured. On the six remaining samples from each implant type, the mechanical properties were evaluated by pushout test on a material testing machine. The samples were loaded at a loading rate of 1 mm/min. The pushout strength was measured and the apparent shear stiffness was calculated. The results were analyzed with a paired-t test. The histology shows osteointegration of surrounding bone with both implant types. Bone was found to grow into the porous space between the beads. Both the Endopore (Innova Corp.) and the EBM (Southern Methodist Univ.) showed similar BIC. The mean BIC for the Endopore (Innova Corp.) and EBM (Southern Methodist Univ.) implant were 35 ± 6% and 32 ± 9%, respectively. It failed to reach statistical significance (p > 0.05). The peak pushout force for Endopore (Innova Corp.) and EBM (Southern Methodist Univ.) implants were 198.80 ± 61.29 N and 243.21 ± 69.75 N, respectively. The apparent shear stiffness between bone and implant for the Endopore (Innova Corp.) and EBM (Southern Methodist Univ.) implants were 577.36 ± 129.99 N/mm; and 584.48 ± 146.63 N/mm, respectively. Neither the peak pushout force nor the apparent shear stiffness of the implants was statistically different between the two groups (p > 0.05). The results suggest that the implants manufactured by EBM (Southern Methodist Univ.) perform equally well as the commercial implant Endopore (Innova Corp.) in this current animal model.Item A Comparison of Frictional Forces During Simulated Cuspid Retraction on a Continuous Edgewise Archwire(1982) Allai, W. Wesley; Garner, LaForrest D.; Sondhi, Anoop; Shanks, James C.; Swartz, Marjorie L.; Barton, PaulThis investigation was designed to compare the force (grams) required to overcome a simulated cuspid retraction assembly capable of three dimensional control during the retraction process. It was hypothesized that a significant difference in the mean retraction values exists between the newer orthodontic alloys of Nitinol, Beta-Titanium, as well as Stainless Steel. One hundred eighty bracket and archwire combinations were examined as follows: Sample # Wire Cross-section Wire Material 30 .016”x.022” Stainless Steel 30 .017”x.025” ” 30 .016”x.022” Nitinol 30 .017”x.025” ” 30 .016”x.022 Beta-Titanium (TMA) 30 .017”x.025” ” A statistically significant difference was shown to exist between all six groups examined regarding the variables of wire size and wire material. The statistical analysis revealed that increasing rectangular archwire cross-sectional size from .016"x.022" to .017"x.025” rectangular wire when simulating canine retraction using an .018" slotted Lewis bracket will lead to significantly greater functional forces. The analysis of wire materials indicated that a significant difference (p=.01) exists between rectangular Beta-Titanium (TMA), Nitinol, and stainless steel during simulated cuspid retraction utilizing a narrow .018" Lewis bracket ligated with A-lastik ligatures. The least frictional force was observed with the .016"x.022" stainless steel test cells. The largest frictional force was found in the .017”'x.025" Beta-Titanium retraction specimens. Nitinol revealed force data intermediate between stainless steel and Beta-Titanium. The maximum resistance assembly developed 2.3 times the minimum frictional force observed. The mean grams of frictional force within these test cells ranged from 55.03 grams for the .016"x.022" retraction assembly to 132.68 grams for the .017"x.025" Beta-Titanium assembly. A topographical scanning electron microscope survey of the brackets and archwires utilized was included to provide qualitative insights into the quantitative results described.Item High Survivorship With a Titanium-encased Alumina Ceramic Bearing for Total Hip Arthroplasty(Springer US, 2014-02) D’Antonio, James A.; Capello, William N.; Naughton, Marybeth; Department of Orthopaedic Surgery, IU School of MedicineBackground Although ceramic-on-ceramic bearings for total hip arthroplasty (THA) show promising results in terms of bearing-surface wear, fracture of the bearing, insertional chips, and squeaking remain a concern. Questions/purposes Our primary objective of this report was to determine overall survivorship of a titanium- encased ceramic-on-ceramic bearing couple. Our secondary objectives were to evaluate for ceramic fracture, insertional chips, osteolysis, and device squeaking. Methods Six surgeons at six institutions implanted 194 patients (209 hips) with an average age of 52 years with cementless hips and alumina ceramic bearings. One hun- dred thirty-seven patients (146 hips) have 10-year followup (70%). We determined Kaplan-Meier survivorship of the bearing surface and implant system and collected radio- graphic and clinical data to evaluate for osteolysis and squeaking. Results Survivorship using revision for any reason as the end point was 97% at 10 years and survivorship end point bearing surface failure or aseptic loosening of 99%. There was one ceramic insert fracture (0.5%), there were no insertional chips, there was no visible osteolysis on AP and lateral radiographs, and there was a 1% patient- self-reported incidence of squeaking at the last clinical followup. Six hips underwent revision (3.7%). Conclusions Ceramic bearings for THA with a titanium- encased insert have high survivorship at 10 years followup and a fracture risk of 0.5%. We found at last followup on routine radiographs no evidence of osteolysis, and no patient has been revised for squeaking or has reported dissatisfaction with the clinical result because of noise. Level of Evidence Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.Item Histological and Mechanical Analysis of Bone/Implant Interface in Female Retired-Breeder Rabbits(1992) Bruch, Christopher G.; Roberts, W. Eugene; Garetto, Lawrence P.; Arbuckle, Gordon R.; Nelson, Charles L.; Shanks, James C.Endosseous implants have been accepted as a viable dental and medical adjunct and are now used for multiple dental applications. The majority are placed in patients of relatively advanced age, and, as such, the increased use of implants has raised questions in the areas of bone healing and metabolism associated with their placement. This study evaluated the mechanical and histological aspects of the bone/metal interface of endosseous titanium implants in compact and trabecular bone. Two implants were placed: one in the distal metaphysis (M) and one 2.0 cm proximal in the diaphysis (D). Right side limbs were subjected to a sham surgery and served as controls. The rabbits were sacrificed at six, 12, and 24 weeks healing time. Multiple fluorochrome labels were given to mark sites of bone formation. At sacrifice, all implants were tested for interface torque strength. Microradiography and fluorescent light microscopy were used to determine percent volume of bone and marrow space, bone/implant interface characteristics, percent labeled bone surface area, and percent labeled bone volume. D implants required about 20 percent more torque to mechanically disrupt the bone/implant interface than M implants. Values were M (combined groups) 33.4 N-cm ±15.5 N-cm, and D (combined groups) 41.5 N-cm ±16.0 N-cm (Mean ±SD, n = 8, p<.07). The percent of bone in direct contact with the implant surface appeared to increase only slightly with time. Direct contact occurred on 11.2%, 9.5% ±8.5% and 13.9% ±6.6% of the M implant surface in six, 12, and 24 week specimens, respectively. Direct contact occured on 11.7%, 10.2% ±2.4% and 19.5% ±0.35% of the D implant surface in six, 12, and 24 week specimens, respectively. Total bone volume in implanted D specimens was less [Exp.= 91.1% ± 3.1%, Cont. = 95.5% ± 0.73% (Mean ±SD)] and marrow space volume was greater [Exp. = 8.9% ±3.02%, Cont. = 4.6% ±0.73% (Mean ±SD)] than in controls (p<.02). The percent labeled bone volume was greater in the implanted specimens than in their controls (p<.001). This difference decreased over time. Implanted D specimens also showed significantly more (p<.001) labeled bone surface area than controls. These findings suggest that when implants are placed in elderly subjects, normally inactive bone becomes very active. Also, it seems that bone quality, not quantity, determines interface strength.Item Low-Temperature Plasma Short Exposure to Decontaminate Peri-Implantitis-Related Multispecies Biofilms on Titanium Surfaces In Vitro(Hindawi, 2022-10-26) Panariello, Beatriz H. D.; Mody, Drashty P.; Eckert, George J.; Witek, Lukasz; Coelho, Paulo G.; Duarte, Simone; Biostatistics and Health Data Science, School of MedicineBackground: The use of low-temperature plasma (LTP) is a novel approach to treating peri-implantitis. LTP disrupts the biofilm while conditioning the surrounding host environment for bone growth around the infected implant. The main objective of this study was to evaluate the antimicrobial properties of LTP on newly formed (24 h), intermediate (3 days), and mature (7 days) peri-implant-related biofilms formed on titanium surfaces. Methods: Actinomyces naeslundii (ATCC 12104), Porphyromonas gingivalis (W83), Streptococcus oralis (ATCC 35037), and Veillonella dispar (ATCC 17748) were cultivated in brain heart infusion supplemented with 1% yeast extract, hemin (0.5 mg/mL), and menadione (5 mg/mL) and kept at 37°C in anaerobic conditions for 24 h. Species were mixed for a final concentration of ~105 colony forming units (CFU)/mL (OD = 0.01), and the bacterial suspension was put in contact with titanium specimens (7.5 mm in diameter by 2 mm in thickness) for biofilm formation. Biofilms were treated with LTP for 1, 3, and 5 min at 3 or 10 mm from plasma tip to sample. Controls were those having no treatment (negative control, NC) and argon flow under the same LTP conditions. Positive controls were those treated with 14 μg/mL amoxicillin and 140 μg/mL metronidazole individually or combined and 0.12% chlorhexidine (n = 6 per group). Biofilms were evaluated by CFU, confocal laser scanning microscopy (CLSM), and fluorescence in situ hybridization (FISH). Comparisons among bacteria; 24 h, 3-day, and 7-day biofilms; and treatments for each biofilm were made. Wilcoxon signed-rank and Wilcoxon rank sum tests were applied (α = 0.05). Results: Bacterial growth was observed in all NC groups, corroborated by FISH. LTP treatment significantly reduced all bacteria species compared to the NC in all biofilm periods and treatment conditions (p ≤ 0.016), and CLSM corroborated these results. Conclusion: Within the limitation of this study, we conclude that LTP application effectively reduces peri-implantitis-related multispecies biofilms on titanium surfaces in vitro.Item Tetracycline-incorporated polymer nanofibers as a potential dental implant surface modifier(Wiley, 2017-10) Bottino, Marco C.; Münchow, Eliseau A.; Albuquerque, Maria T.P.; Kamocki, Krzysztof; Shahi, Rana; Gregory, Richard L.; Chu, Tien-Min G.; Pankajakshan, Divya; Biomedical Sciences and Comprehensive Care, School of DentistryThis study investigated the antimicrobial and osteogenic properties of titanium (Ti) disks superficially modified with tetracycline (TCH)-incorporated polymer nanofibers. The experiments were carried out in two phases. The first phase dealt with the synthesis and characterization (i.e., morphology, mechanical strength, drug release, antimicrobial activity, and cytocompatibility) of TCH-incorporated fibers. The second phase was dedicated to evaluating both the antimicrobial and murine-derived osteoprecursor cell (MC3T3-E1) response of Ti-modified with TCH-incorporated fibers. TCH was successfully incorporated into the submicron-sized and cytocompatible fibers. All TCH-incorporated mats presented significant antimicrobial activity against periodontal pathogens. The antimicrobial potential of the TCH-incorporated fibers-modified Ti was influenced by both the TCH concentration and bacteria tested. At days 5 and 7, a significant increase in MC3T3-E1 cell number was observed for TCH-incorporated nanofibers-modified Ti disks when compared to that of TCH-free nanofibers-modified Ti-disks and bare Ti. A significant increase in alkaline phosphatase (ALP) levels on the Ti disks modified with TCH-incorporated nanofiber on days 7 and 14 was seen, suggesting that the proposed surface promotes early osteogenic differentiation. Collectively, the data suggest that TCH-incorporated nanofibers could function as an antimicrobial surface modifier and osteogenic inducer for Ti dental implants.Item The Oxidative Response of Human Monocytes to Surface Modified Commercially Pure Titanium(Frontiers Media, 2021-06-02) De Poi, Robert P.; Kowolik, Michael; Oshida, Yoshiki; El Kholy, Karim; Periodontology, School of DentistryCellular responses to implanted biomaterials are key to understanding osseointegration. The aim of this investigation was to determine the in vitro priming and activation of the respiratory burst activity of monocytes in response to surface-modified titanium. Human peripheral blood monocytes of healthy blood donors were separated, then incubated with surface-modified grade 2 commercially pure titanium (CPT) disks with a range of known surface energies and surface roughness for 30- or 60-min. Secondary stimulation by phorbol 12-myrisate 13-acetate (PMA) following the priming phase, and luminol-enhanced-chemiluminescence (LCL) was used to monitor oxygen-dependent activity. Comparison among groups was made by incubation time using one-way ANOVA. One sample from each group for each phase of the experiment was viewed under scanning electron microscopy (SEM) and qualitative comparisons made. The results indicate that titanium is capable of priming peripheral blood monocytes following 60-min incubation. In contrast, 30 min incubation time lead to reduced LCL on secondary stimulation as compared to cells alone. At both time intervals, the disk with the lowest surface energy produced significantly less LCL compared to other samples. SEM examination revealed differences in surface morphology at different time points but not between differently surface-modified disks. These results are consistent with the hypothesis that the titanium surface characteristics influenced the monocyte activity, which may be important in regulating the healing response to these materials.